This was a feature on console (at least xbox 1) and it made sense. Touch a door, open. Once you are through the door, close. Simple. I feel as though this feature should also be included in the pc version and console 1.3 updates.
Smart cursor is not that smart sometimes. If you have many points of interest nearby it could choose something you don't want to open/switch/use. On consoles i always had a problem when being near chests, which i think get priority for "using". I simply cannot get on rails when near chests, not to mention open doors, but luckily the second one is not necessary.I hated this feature. It let in monsters and stopped me from using doors as launch points and walls. Smart Cursor already auto-locks onto any nearby doors.
It's convenient this way. Sure you could break a block and place another one in the same spot, but the devs thought up block swap (For 1.3.6). Try to look at it from that perspective, not a Post-Skeletron one.Same can be achieved with 2 pressure plates and 5 pieces of wire.